iOS Custom gesture recognizer measure length of longpress - ios

Question

In my app i want to create a custom gesture recognizer that recognizes a long press followed by a swipe.
I need to measure if the length of the long press is more than 1 second. If it is, then call a function and wait for the swipe action to begin.
My problem is that I the only way i know now how long the press was is by extracting the timestamp of touchesBegan from touchesMoved. However i want to know that elapsed time before touchesMoved gets called.
Is there a way to know the length of the tap before the touchesMoved is called?
Thanks in advance!

Answer 1

you can use may code, it can use, but maybe you should deal with some details
in the .h file you should add these ivar:
TestView *aView ;//the view which you press
NSThread *timerThread;
NSTimer *touchTimer;
NSDate *touchStartTime;
CGPoint touchStartPoint;
CGPoint lastTouchPoint;
in the .m file you should add these method:
- (void)doSomething
{
NSLog(#"Long press!!!");
}
- (void)startTimerThead{
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
NSRunLoop *runLoop = [NSRunLoop currentRunLoop];
touchTimer = [NSTimer scheduledTimerWithTimeInterval:0.2
target:self
selector:#selector(checkTouchTime:)
userInfo:nil repeats:YES];
[runLoop run];
[pool release];
}
- (void)stopTouchTimer{
if (touchTimer != nil) {
[touchTimer invalidate];
touchTimer = nil;
}
if (timerThread != nil) {
[timerThread cancel];
[timerThread release];
timerThread = nil;
}
}
#define DELETE_ACTIVING_TIME 1.0
- (void)checkTouchTime:(NSTimer*)timer{
NSDate *nowDate = [NSDate date];
NSTimeInterval didTouchTime = [nowDate timeIntervalSinceDate:touchStartTime];
if (didTouchTime > DELETE_ACTIVING_TIME){
[self stopTouchTimer];
[self doSomething];
}
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
UIView *touchView = [touch view];
if ([touchView isKindOfClass:[TestView class]]) {
touchStartTime = [[NSDate date] retain];
if (nil == timerThread) {
timerThread = [[NSThread alloc] initWithTarget:self selector:#selector(startTimerThead) object:nil];
[timerThread start];
}
}
touchStartPoint = [touch locationInView:self.view];
lastTouchPoint = touchStartPoint;
}
#define TOUCH_MOVE_EFFECT_DIST 10.0f
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *touch = [touches anyObject];
CGPoint movedPoint = [touch locationInView:self.view];
CGPoint deltaVector = CGPointMake(movedPoint.x - touchStartPoint.x, movedPoint.y - touchStartPoint.y);
if (fabsf(deltaVector.x) > TOUCH_MOVE_EFFECT_DIST
|| fabsf(deltaVector.y) > TOUCH_MOVE_EFFECT_DIST)
{
[self stopTouchTimer];
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
UITouch *touch = [touches anyObject];
UIView *touchView = [touch view];
CGPoint movedPoint = [touch locationInView:self.view];
CGPoint deltaVector = CGPointMake(movedPoint.x - touchStartPoint.x, movedPoint.y - touchStartPoint.y);
if ([touchView isKindOfClass:[TestView class]]) {
if (fabsf(deltaVector.x) < TOUCH_MOVE_EFFECT_DIST
&& fabsf(deltaVector.y) < TOUCH_MOVE_EFFECT_DIST) {
[self stopTouchTimer];
}
}
}